Aleknavičiūtė, Daiva, and Stanislovas Norgėla. “Normal Form of Formulas of Pure Hybrid Logic”. Lietuvos matematikos rinkinys 47, no. spec. (June 14, 2021): 341–345. Accessed October 29, 2025. https://test.zurnalai.vu.lt/LMR/article/view/24225.